Overcoming the quantum projection noise (QPN) limit without preparation of the spin-squeezed state

N. Shiga; M. Takeuchi

doi:10.1117/12.892674

12 September 2011 Overcoming the quantum projection noise (QPN) limit without preparation of the spin-squeezed state

N. Shiga, M. Takeuchi

Proceedings Volume 8132, Time and Frequency Metrology III; 813207 (2011) https://doi.org/10.1117/12.892674
Event: SPIE Optical Engineering + Applications, 2011, San Diego, California, United States

Abstract

Atomic clocks have reached the Quantum Projection Noise (QPN) limit of stability and it has been proposed to use the entangled atomic ensemble in order to overcome the QPN limit. We have proposed a new method to lock the phase of the Local Oscillator (LO) to the atomic phase and call, "atomic phase lock (APL)." This APL could possibly overcome the QPN limit without need of preparing the entangled atomic ensemble. Traditional Ramsey method destroys the coherence of the atomic spin due to the projection measurement at each cycle. This destruction and initialization of the phase at each cycle introduce additional noise and the performance of the atomic clock is limited at the white frequency noise level. APL employs dispersion measurements, i.e. Faraday rotation, in order to measure the phase difference without destroying the atomic phase. By repeating the measurement cycle with sufficiently small dead time, one can suppress the LO noise down to white phase noise level, achieving the τ^-1 dependence of the Allan variance that can eventually overcome the QPN limit in long term. We are preparing a proof-of-principle experiment using the ensemble of trapped 171Yb⁺ ions with hyperfine splitting (12.6 GHz) as a clock transition and report the current status of the experiment as well.

Citation Download Citation

N. Shiga and M. Takeuchi "Overcoming the quantum projection noise (QPN) limit without preparation of the spin-squeezed state", Proc. SPIE 8132, Time and Frequency Metrology III, 813207 (12 September 2011); https://doi.org/10.1117/12.892674

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
6 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Ions

Chemical species

Laser beam diagnostics

Signal to noise ratio

Atomic clocks

Phase measurement

Clocks

Show All Keywords

Keywords/Phrases

Search In:

Publication Years